メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.1437500 44.0041667, 142.1500000 44.0041667, 142.1500000 44.0083333, 142.1437500 44.0083333, 142.1437500 44.0041667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral